A spike in air pollution is threatening to make the city gasp for breath. Levels of particulate matter less than 10 microns in size (PM10) have increased manifold since October this year as compared to levels last year. The December figures have crossed the danger mark for those suffering from respiratory problems.
Experts warn that suspended particles less than 10 microns in size cause more harm because of their ability to reach deep inside the lungs.
Dust-defence mechanisms like cilia (fine hair-like structures) in the trachea (windpipe) are defenceless against a surfeit of these fine dust particles.
Data from the System of Air Quality Forecasting and Research (SAFAR) reveals average PM10 levels in October and November were 54.43µg/m3 and 97.83 µg/m3 respectively in 2013 and climbed to 89.14µg/m3 and 105.84 µg/m3 in the corresponding months of this year. The average in December 2013 was 114.06 µg/m3. This December, so far, it is hovering at 122.95 µg/m3.
Dr Gufran Beig, Project Director, SAFAR said researchers had observed that on some days during these months air quality of Pune was listed as ‘poor’ indicating health risk to sensitive group of people.
Children and adults active outdoors and people with respiratory disease are at a greater risk, Neha Parkhi, senior programme officer at SAFAR said.
The monitoring and forecasting by SAFAR is done at ten stations in the city for major gaseous pollutants like oxides of nitrogen, carbon monoxide, benzene and other hydrocarbons, besides particulate matter. A close eye is kept on PM10 and the more harmful PM2.5.
Level of any gaseous pollutant is defined by the Air Quality Index (AQI) at a scale of 0-500.
As temperature goes down in winter, higher levels of particulate matter are recorded at ground level. When temperature is lower, upward movement of pollutants from various sources slows down. If there is no wind activity, horizontal dispersal also slows down. This leads to accumulation of particulate matter near the earth’s surface, causing a haze, explained Beig. There is higher concentration of particulate matter near the earth’s surface, or within the breathing range, so more particles enter the lungs.
Particles larger than PM10 are filtered out in the upper layers of respiratory tract. People with lung conditions — for instance asthma or chronic obstructive pulmonary disease — are at risk. There are associated risks for people with heart disease, researchers said.